US stock markets will remain closed for the fourth and possibly final day today.
Wall Street's workforce are battling uncertainty over the future after an attack crushed the world's financial heart and killed perhaps thousands.
The world's most powerful stock exchanges - the New York Stock Exchange and the Nasdaq stock market - assured investors they would reopen for business on Monday if a slew of tests over the weekend are successful.
But some investors wondered if such a resumption would be possible just six days after hijacked planes toppled the twin towers of the World Trade Center and left the financial district in a smoking ruin.
"The mood obviously is grim," said Mr Peter Cardillo, a director of research at Westfalia Investments, who lost his offices in the attack.
"It's not going to be easy to go back to the Wall street area and actually see a war zone. I was there when it happened, I was walking in the smoke and the debris and the dust".
Wall Street's workforce of 180,000 people and the rest of the US planned today to commemorate the victims of the worst attack on the United States since Pearl Harbor.
Many Wall Street gurus are expecting declines, but a handful have actually been predicting rises with investors possibly staging a patriotic rally.